Highly articulated robotic probes and methods of production and use of such probes

ABSTRACT

A highly articulated robotic probe comprises an outer sleeve and an inner core. The outer sleeve and inner core include a plurality of links. The links of the outer sleeve and inner core are configured to pivot relative to one another. Various characteristics of the links determine the overall pivot angle of the articulated probe. Each of the plurality of links may have one or more channels. The channels form a semi-continuous passage from link to link and are configured to receive an elongated member such as an inner core, tool or cable. One or more cables may be used to control the outer links of the outer sleeve and the inner links of the inner core. Various characteristics of the cables determine the overall performance of the articulated probe.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/587,166, filed on Dec. 31, 2014, which is acontinuation application of U.S. patent application Ser. No. 13/880,525,filed on Sep. 17, 2013, which claims the benefit of United States PCTapplication serial number PCT/US2011/057282, filed on Oct. 21, 2011,which claims the benefit of U.S. Provisional Application No. 61/406,032,filed Oct. 22, 2010, the content of which is incorporated herein byreference in its entirety.

United States PCT application serial number PCT/US2011/057282, filed onOct. 21, 2011 also claims the benefit of U.S. Provisional ApplicationNo. 61/534,032, filed Sep. 13, 2011, the content of which isincorporated herein by reference in its entirety.

United States PCT application serial number PCT/US2011/057282, filed onOct. 21, 2011 also claims the benefit of U.S. Provisional ApplicationNo. 61/412,733, filed Nov. 11, 2010, the content of which isincorporated herein by reference in its entirety.

United States PCT application serial number PCT/US2011/057282, filed onOct. 21, 2011 also claims the benefit of U.S. Provisional ApplicationNo. 61/472,344, filed Apr. 6, 2011, the content of which is incorporatedherein by reference in its entirety.

United States PCT application serial number PCT/US2011/057282, filed onOct. 21, 2011 also claims the benefit of U.S. Provisional ApplicationNo. 61/492,578, filed Jun. 2, 2011, the content of which is incorporatedherein by reference in its entirety.

This application is related to U.S. Provisional Application No.61/368,257, filed Jul. 28, 2010, the content of which is incorporatedherein by reference in its entirety.

This application is related to PCT Application No PCT/US2011/044811,filed Jul. 21, 2011, the content of which is incorporated herein byreference in its entirety.

This application is related to U.S. patent application Ser. No.11/630,279, filed Dec. 20, 2006, published as U.S. Patent ApplicationPublication No. 2009/0171151, the content of which is incorporatedherein by reference in its entirety.

FIELD

Embodiments relate generally to the field of robotics and, moreparticularly, to three dimensional, flexible, steerable robotic devices.

BACKGROUND

There are numerous types of steerable multi-linked probes, and suchdevices are utilized in a variety of different applications. RobertSturges' U.S. Pat. No. 5,759,151, which is hereby incorporated byreference in its entirety, discloses a flexible, steerable device forconducting exploratory procedures. The device includes at least onespine, each having stiffening means for selectively rendering the spinerigid and flexible along its length. A flexible sheath surrounds thespine and is axially slidably moveable relative to the spine so that thesheath will follow and conform to the shape of a spine in the rigidstate and resist further flexure when the spine is in a relaxed state. Asteerable distal tip is provided on the distal end of the device.Controls for the distal tip are mounted on the proximal end of thedevice. Mechanisms are provided on the distal end of the device forselectively activating and deactivating the stiffening means of thespine. An instrument conduit may be mounted on the sheath. HowardChoset's U.S. patent application Ser. No. 11/630,279, which is herebyincorporated by reference in its entirety, discloses a feeder mechanismfor advancing and retracting both an inner core and an outer sleeve, aswell as selectively applying tension to control cables used for steeringand causing either the inner core or outer sleeve to transition betweena rigid state and a limp state.

U.S. Pat. No. 6,610,007, incorporated herein by reference, discloses asteerable endoscope having an elongated body with a selectivelysteerable distal portion and an automatically controlled proximalportion. The endoscope body is inserted into a patient and theselectively steerable distal portion is used to select a desired pathwithin the patient's body. When the endoscope body is advanced, anelectronic motion controller operates the automatically controlledproximal portion to assume the selected curve of the selectivelysteerable distal portion. Another desired path is selected with theselectively steerable distal portion and the endoscope body is advancedagain. As the endoscope body is further advanced, the selected curvespropagate proximally along the endoscope body, and when the endoscopebody is withdrawn proximally, the selected curves propagate distallyalong the endoscope body. This creates a serpentine motion in theendoscope body allowing it to negotiate tortuous curves along a desiredpath through or around and between organs within the body.

For medical use and other critical applications, it is extremelyimportant that each device not only perform as intended and within knownspecifications, but have repeatable performance and otherwise consistentoperation from use to use. For these and other reasons, there is a needfor improved systems, devices, and methods.

SUMMARY

According to one embodiment, an articulated probe having at least aportion configured to be controllably rigid and flexible, includes aninner core having a plurality of inner links; an inner cable extendingthrough the plurality of inner links and configured to control the innercore; an outer sleeve having a plurality of outer links; and a pluralityof outer cables extending through the plurality of outer links andconfigured to control the outer sleeve, wherein the inner cable has atensile strength greater than each of the individual outer cables.

In some embodiments, the tensile strength of the inner cable isapproximately equal to a combined tensile strength of the plurality ofouter cables.

In some embodiments, each of the plurality of outer cables hasapproximately the same tensile strength.

In some embodiments, the tensile strength of each of the plurality ofouter cables is approximately 1/Nth of a tensile strength of the innercable, where N is the number of outer cables.

In some embodiments, each of the plurality of outer cables hasapproximately the same cross-sectional area.

In some embodiments, the cross-sectional area of each of the pluralityof outer cables is approximately 1/Nth of a cross-sectional area of theinner cable, where N is the number of outer cables.

In some embodiments, the inner cable and the plurality of outer cablesare comprised of at least one of steel, polyethylene, nylon andfluorocarbons.

According to another embodiment, an articulated probe includes aplurality of links configured to pivot relative to one another through amaximum pivot angle; and an elongated member, wherein at least two ofthe plurality of links includes a channel for receiving the elongatedmember therein, and wherein the channel in each of the plurality oflinks is tapered in an amount sufficient to permit the plurality oflinks to pivot through the maximum pivot angle while providing asubstantially continuous surface between the channels of the links forthe elongated member.

In some embodiments, the articulated probe comprises an inner corecomprising a plurality of inner links, and wherein the channel ispositioned within at least two of the plurality of inner links.

In some embodiments, the articulated probe comprises an outer sleevecomprising a plurality of outer links, and wherein the channel ispositioned within at least two of the plurality of outer links.

In some embodiments, the articulated probe comprises an outer sleevecomprising a plurality of outer links; an inner core comprising aplurality of inner links; wherein the channel is positioned between atleast two of the plurality of outer links and at least two of theplurality of inner links.

In some embodiments, the at least two of the plurality of linkscomprises a side port and the channel is positioned within the sideport.

In some embodiments, the channel comprises a recess in the at least twoof the plurality of links.

In some embodiments, the taper is approximately twice the maximum pivotangle.

In some embodiments, the taper is approximately 26 degrees and themaximum pivot angle is approximately 13 degrees.

In some embodiments, a diameter of the elongated member is less than adiameter of the channels of the links.

In some embodiments, the elongated member includes at least one of atool and a cable.

In some embodiments, the elongated member includes an inner core formedof a plurality of inner links.

According to yet another embodiment, an articulated probe with a probecentral axis includes an inner core having a plurality of inner linksconfigured to pivot relative to one another and the probe central axisthrough an inner maximum pivot angle; and an outer sleeve having aplurality of outer links configured to pivot relative to one another andthe probe central axis through an outer maximum pivot angle, and whereinthe inner maximum pivot angle is no less than the outer maximum pivotangle.

In some embodiments, the plurality of outer links in the outer sleeveincludes: a first outer link with a first central axis that can alignwith the probe central axis, the first outer link including an outwardlyextending first flange with a first engagement surface extendingradically outward relative to the first central axis; and a second outerlink with a second central axis that can align with the probe centralaxis, the second outer link including an outwardly extending secondflange with a second engagement surface extending radically outwardrelative to the second central axis, wherein the first outer link andsecond outer link are configured to permit the first and second outerlinks to pivot relative to one another and the probe central axisthrough the outer maximum pivot angle until the first engagement surfaceengages the second engagement surface.

In some embodiments, the first engagement surface tapers relative to aline perpendicular to the first central axis.

In some embodiments, the second engagement surface tapers relative to aline perpendicular to the second central axis.

In some embodiments, the first engagement surface tapers approximately6.5° degrees and the second engagement surface tapers approximately 6.5°degrees.

In some embodiments, the outer maximum pivot angle is no greater thanapproximately 13 degrees.

In some embodiments, at least one of the plurality of inner links andthe plurality of outer links includes channels configured to receive anelongated member therein, wherein the channels are tapered in an amountsufficient to permit pivoting through the outer maximum pivot anglewhile providing a substantially continuous surface between the channelsfor the elongated member.

According to another embodiment, an articulated probe, includes aplurality of links configured to pivot relative to one another, whereinthe plurality of links includes a first link having a first concaveportion and a first convex portion; a second link have a second concaveportion and second convex portion, wherein the first convex portion ofthe first link pivotally engages the second concave portion of thesecond link, and wherein the first convex portion has a radius ofcurvature no greater than a radius of curvature of the second concaveportion.

In some embodiments, each of the plurality of links has a concaveportion and a convex portion that engage corresponding convex andconcave portions of adjacent links, and the convex portions each have aradius of curvature no greater than a radius of curvature of thecorresponding concave portion.

In another embodiment, a method of performing a surgical procedurecomprises: selecting the articulated probe as described in any of theembodiments herein; and manipulating the probe to position at least onetool.

In another embodiment, a method of producing a link for an articulatedprobe formed of a plurality of links includes the steps of molding thelink in molding device, including forming at least one engagementsurface configured to engage an adjacent link in the articulated probe;ejecting the link from the molding device by pressing at least oneejection pin against an ejection surface of the link that will notengage an adjacent link in the articulated probe.

In some embodiments, the ejection surface is located in a recess in thelink.

In another aspect, embodiments are directed to an articulated probe asdescribed in reference to the figures.

In another aspect, embodiments are directed to a method of performing amedical procedure as described in reference to the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of embodimentsof the present inventive concepts will be apparent from the moreparticular description of embodiments, as illustrated in theaccompanying drawings in which like reference characters refer to thesame elements throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the embodiments.

FIGS. 1A-1C are graphic demonstrations of a highly articulated probedevice, in accordance with the present inventive concepts;

FIGS. 2A-2B illustrate various configurations assumed by a highlyarticulated probe, in accordance with the present inventive concepts;

FIGS. 3A-3D illustrate various views of a link of an outer sleeve, inaccordance with the present inventive concepts;

FIGS. 4A and 4B illustrate end and cross-sectional views, respectively,of a link of an inner core, in accordance with the present inventiveconcepts;

FIGS. 5A and 5B illustrates one example of a feeder mechanism, inaccordance with the present inventive concepts;

FIG. 6 illustrates devices for controlling the tension on cables, inaccordance with the present inventive concepts;

FIG. 7 illustrates devices for controlling the tension on the cables ofthe outer sleeve, consistent with the present invention;

FIG. 8 illustrates a device for controlling the tension on the cable ofthe inner sleeve, in accordance with the present inventive concepts;

FIG. 9 is a block diagram illustrating the components of a controlsystem and the flow of information between those components, inaccordance with the present inventive concepts;

FIGS. 10A and 10B illustrate a cross section of an articulated probeaccording to an embodiment, in accordance with the present inventiveconcepts.

FIGS. 11A and 11B illustrate a cross section of an articulated probeaccording to an embodiment, in accordance with the present inventiveconcepts.

FIGS. 12A-12B illustrate a cross section of an outer sleeve according toan embodiment, in accordance with the present inventive concepts.

FIGS. 13A-13B illustrate a cross section of an inner core according toan embodiment, in accordance with the present inventive concepts.

FIG. 13C illustrates a view of an inner link having an inner cablepositioned in an outer link having a plurality of outer cables accordingto an embodiment.

FIGS. 14A-14I illustrate various views of an outer link, according to anembodiment, in accordance with the present inventive concepts.

FIGS. 15A-15J illustrate various views of an outer link transitionsegment, according to an embodiment, in accordance with the presentinventive concepts.

FIGS. 16A-16K illustrate various views of an outer link with tool sideports, according to an embodiment, in accordance with the presentinventive concepts.

FIGS. 17A-17I illustrate various views of an inner link, according to anembodiment, in accordance with the present inventive concepts.

FIG. 18 is a flow chart for producing a link for an articulated probeaccording to an embodiment, in accordance with the present inventiveconcepts.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present inventive concepts will now be described morefully hereinafter with reference to the accompanying drawings. Thisinventive concepts may, however, be embodied in different forms andshould not be construed as limited to the embodiments set forth herein.Like numbers refer to like elements throughout the specification.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various limitations, elements,components, regions, layers and/or sections, these limitations,elements, components, regions, layers and/or sections should not belimited by these terms. These terms are only used to distinguish onelimitation, element, component, region, layer or section from anotherlimitation, element, component, region, layer or section. Thus, a firstlimitation, element, component, region, layer or section discussed belowcould be termed a second limitation, element, component, region, layeror section, and vice-versa, without departing from the teachings of thepresent application.

It will be understood that when an element is referred to as being “on”or “connected” or “coupled” to another element, it can be directly on orconnected or coupled to the other element or intervening elements can bepresent. In contrast, when an element is referred to as being “directlyon” or “directly connected” or “directly coupled” to another element,there are no intervening elements present. Other words used to describethe relationship between elements should be interpreted in a likefashion (e.g., “between” versus “directly between,” “adjacent” versus“directly adjacent,” etc.). When an element is referred to herein asbeing “over” another element, it can be over or under the other element,and either directly coupled to the other element, or interveningelements may be present, or the elements may be spaced apart by a voidor gap.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting of the invention. As usedherein, the singular forms “a,” “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof

Overview of Highly Articulated Robotic Probe

A highly articulated robotic probe 10, according to one embodiment shownin FIGS. 1A-1C, is essentially two concentric mechanisms, an outer oneand an inner one, each of which can be viewed as a steerable mechanism.FIGS. 1A-1C show the concept of how different embodiments of the probe10 operate. Referring to FIG. 1A, the inner mechanism is referred to asa first mechanism, an inner core or inner core mechanism 12. The outermechanism is referred to as a second mechanism, an outer sleeve or outersleeve mechanism 14. Each mechanism can alternate between being rigidand limp. In the rigid mode or state, the mechanism is just that—rigid.In the limp mode or state, the mechanism is highly flexible and thuseither assumes the shape of its surroundings or can be reshaped. Itshould be noted that the term “limp” as used herein does not denote astructure that passively assumes a particular configuration dependentupon gravity and the shape of its environment; rather, the “limp”structures described in this application are capable of assumingpositions and configurations that are desired by the operator of thedevice, and therefore are articulated and controlled rather than flaccidand passive.

With this probe 10, one mechanism starts limp and the other startsrigid. For the sake of explanation, assume the outer sleeve 14 is rigidand the inner core 12 is limp, as seen in step 1 in FIG. 1A. Now, theinner core 12 is both pushed forward by a feeding mechanism 16,described below, and its “head” or distal end is steered, as seen instep 2 in FIG. 1A. Now, the inner core 12 is made rigid and the outersleeve 14 is made limp. The outer sleeve 14 is then pushed forward untilit catches up or is coextensive with the inner core 12, as seen in step3 in FIG. 1A. Now, the outer sleeve 14 is made rigid, the inner core 12limp, and the procedure then repeats. One variation of this approach isto have the outer sleeve 14 be steerable as well. The operation of sucha device is illustrated in FIG. 1B. In FIG. 1B it is seen that eachmechanism is capable of catching up to the other and then advancing onelink beyond. According to one embodiment, the outer sleeve 14 issteerable and the inner core 12 is not. The operation of such a deviceis shown in FIG. 1C.

In medical applications, once the probe 10 arrives at a desiredlocation, the operator, typically a surgeon, can slide one or more toolsthrough one or more channels of outer sleeve 14, inner core 12, or achannel formed between outer sleeve 14 and inner core 12, such as toperform various diagnostic and/or therapeutic procedures. In addition toclinical procedures such as surgery, probe 10 can be used in numerousapplications including but not limited to: engine inspection, repair orretrofitting; tank inspection and repair; spying and surveillanceapplications; bomb disarming; inspection or repair in tightly confinedspaces such as submarine compartments or nuclear weapons; structuralinspections such as building inspections; hazardous waste remediation;biological sample recovery such as anthrax recovery; and combination ofthese. Clearly, the device of the present disclosure has a wide varietyof applications and should not be taken as being limited to anyparticular application.

Inner core 12 and/or outer sleeve 14 are steerable and inner core 12 andouter sleeve 14 can each be made both rigid and limp, allowing probe 10to drive anywhere in three-dimensions. Probe 10 can “remember” itsprevious configurations and for this reason, probe 10 can go anywhere ina three dimensional volume such as the intracavity spaces in the body ofa patient such as a human patient. FIGS. 2A-2B illustrate examples ofvarious configurations assumable by probe 10.

As can be seen in FIGS. 3A-3D and 4A and 4B, according to oneembodiment, the outer sleeve 14 and inner core 12, respectively, can bemade up of concentric cylinders, links 22, 24, respectively, althoughlinks of other shapes may be used, e.g. a dog bone configuration (notshown) as well as links of a type that are not concentric, e.g. backboneconfiguration, among others. The ends of the links 22, 24 are not flatbut instead one end 26 is an “outer” or convex hemisphere and the otherend 28 is an “inner” or concave hemisphere, both typically with similarradius of curvature. The links 22, or links, of the outer sleeve 14 are“chained” back-to-back such that the concave end 28 of one mates withthe convex end 26 of an adjacent link. Similarly, the links 24, orlinks, of the inner core 12 are chained back-to-back. The result is aspherical-like joint, from a kinematic point of view. In the currentembodiment, each link is able to rotate on the adjacent link's head,acting as a spherical joint with approximately 10-20 degrees range ofmotion in any direction, although other ranges of motion are possibleand potentially advantageous. According to one embodiment, the links 22have a plurality of channels 30 extending therethrough for controlcables or elongate devices such as elongate tools.

The heads (i.e. the distal links) of either or both the outer sleeve 14and the inner core 12 are steerable using three cables which areattached at, for example, 120° from each other. As can be seen in FIGS.3A-3D, there are three small cylindrical channels 30, 32, respectively,for cables to pass through. In the version of the device shown in FIGS.4A and 4B, the inner link 24 has only one cable, in which case there isonly one hole 34 through its center.

It will be appreciated that although the embodiment described aboveutilizes cables such as conductive or non-conductive wires or otherflexible filamentous structure, alternative means of manipulating thelimp elements, such as miniature pneumatic or hydraulic pistons or othermechanical linkages situated between individual links, can be employedwithout falling outside the scope of the present inventive concepts.

The links, and hence probe 10, can be made out of virtually anymaterial, including plastic or other magnetic resonance imagingcompatible material. The outer sleeve 14 may assume a broad range ofdiameters, typically greater than 5 mm. Similarly, inner core 12 mayassume a broad range of diameters, less than the diameter of outersleeve 14 and typically more than 3 mm. The total number of links canvary over a large range but is typically greater than 10 links.

As noted, the inner core 12 and outer sleeve 14 can be made rigid orlimp using cables or other flexible filament structures. In oneembodiment, outer sleeve 14 consists of a set of links 22 strung onthree cables. The three cables are typically 120 degrees apart, makingit possible to steer in any direction. Radius of curvature of probe 10is dependent on a number of factors including length of links 22 as wellas mating dimensions between the ends of mating links 22. When thecables are pulled toward the back of the outer sleeve 14, the links 22are pulled toward each other. When the pulling force increases, thefriction force between adjacent links 22 increases until the entireouter sleeve 14 stiffens (i.e. enters the rigid mode). When the pullingforce is released, the outer sleeve 14 becomes limp. Thus, the cablestogether with their respective tensioning assemblies (e.g. motor drivenputties) form a locking device. The tensioning assemblies, along withthe electronics for controlling the tensioning assemblies, comprise ameans for controlling the tension on the cable. When the outer sleeve 14is positioned one link in front of the inner core 12, and the inner core12 is stiff, the distal link of the outer sleeve 14 can be oriented bypulling one or more of the three cables. In addition to advancing orretracting cable, the magnitude of the pulling force which is exerted oneach cable can be monitored or controlled. By pulling the three cableswith the same magnitude, the outer sleeve 14 becomes stiff withoutchanging its shape.

The inner core 12, like the outer sleeve 14, consists of a set of links.According to one embodiment, in contrast to the outer sleeve 14, theinner core 12 does not need (but may optionally have) a steeringability. The inner core 12 does need the ability to change from rigidmode, to limp mode, and back. Therefore, in embodiments where the innercore 12 need not be steerable, the links of the inner core 12 may bestrung on a single cable, which enables a reduced overall diameter forprobe 10.

Overview of Feeding Mechanism

As mentioned above, a feeding mechanism 16 can be used to control theprobe 10. One type of feeding mechanism 16, shown in FIGS. 5A and 5B,inserts and retracts the probe 10 into and out of, respectively, aregion of interest such as the esophagus, the peritoneal space, thepericardial cavity, or another internal space of a patient. The feeder16 has two movable carts. A first cart 42, carried in a first fixed tray43, advances and retracts the outer sleeve 14 while a second cart 44,carried in a second fixed tray 45, advances and retracts the inner core12. Each cart 42, 44, and hence each of the inner core 12 and outersleeve 14, is driven independently by separate linear actuators 46, 48respectively. The linear actuators 46, 48 may carry shaft encoders (notshown) used for position control as is known. Alternatively oradditionally, motor current may be monitored to determine a value fortension in a cable used to control position. Cable tension may bemonitored with one or more sensors such as a load cell. Numerouspositioning and other sensors may be included to provide informationrelative to cable tension; cart position; probe orientation andconfiguration; and other system parameters. Typical sensors include butare not limited to: optical sensors; magnetic sensors such as Halleffect sensors; force and pressure sensors such as accelerometers,strain gauges and mechanical switches; and combinations of these. One ormore sensors may be positioned in multiple locations including but notlimited to: feeding mechanism 16, inner core 12 and outer sleeve 14.

Each of the carts 42, 44 carries one or more motors necessary forcontrolling the cables of the inner core 12 and outer sleeve 14. Forexample, as seen in FIG. 6 and FIG. 7, the cart 42 carries motors 50,51, 52 which control the tension on cables 54, 55, 56 of outer sleeve14. As shown in FIG. 8, second cart 44 has a motor 58 for controllingthe tension on cable 59 of the inner core 12. Each of the motors 50, 51,52 and 58 may be provided with shaft encoders (not shown) used forposition control as is known. In an embodiment where the inner core 12is steerable, the inner core 12 requires two or more motors (e.g. totension two or more cables) or another cable tensioning mechanism.

FIG. 9 is a block diagram illustrating the components of one embodimentof a control system and the flow of information between thosecomponents. The feeding mechanism 16 interfaces with a control computer62 through a bus conversion module 64. Outgoing data from the feedingmechanism 16 is input to the module 64 for conversion to the USB and isthen input to a USB port 66 on the computer 62. Incoming data to controlsoftware 68 may include motor current data, motor encoder data and/orcable tension data associated with each of the cables in the feedingmechanism 16. Alternatively or additionally, incoming data to controlsoftware 68 may include data from one or more sensors located in feedingmechanism 16, inner core 12 or outer sleeve 14. Joystick data (positiondata) may also be received from a joystick 70. A monitor 72 may beresponsive to video data from a camera mounted on the distal end of theouter sleeve 14 and/or inner core 12 to provide visual feedback to auser regarding the position of the distal end of the probe 10. Thecontrol software 68 may output motor current limit commands and motorposition commands which are input to the feeding mechanism 16.

Inner Core and Outer Sleeve

FIGS. 10A-11B illustrate an embodiment of the articulated probe 10 withthe inner core 12 and the outer sleeve 14. The inner core 12 has aplurality of inner links 100 (preferably at least three, and, in someembodiments, fifty or more). The outer sleeve 14 has a plurality ofouter links 104 (preferably at least three, and, in some embodiments,forty or more).

With regard to the outer links, FIGS. 14A-16J illustrate various viewsof presently preferred embodiments of such outer links 104, 132. Theseembodiments of the outer links are similar to those discussed in theoverview above. However, these embodiments differ in some significantaspects from those discussed above, as well as from each other. Thepresent embodiments of the outer links 104, 132 can be combined to forma unique outer sleeve 14, such as shown in FIG. 11A. In particular,FIGS. 16A-16K illustrate various views of outer links 104 with tool sideports 128. The tool side ports 128 can be used to receive and guidetools. FIGS. 15A-15J illustrate various views of transition outer links132. As shown in FIG. 11A, a plurality of transition outer links 132 canbe positioned adjacent an outer link 104 with tool side ports 128. Thetransition outer link 132 can have one or more recesses 130 thataccommodates and funnels elongated members, such as tools, into the toolside port 128 of the outer link 104. For example, the inner diameter ofthe outer link 104, 132 preferably is in the range of 0.10-2.00 inches,and more preferably the inner diameter, is approximately 0.394 inches.The outer diameter of the outer link 104, 132 preferably is in the rangeof 0.20-3.00 inches, and more preferably the outer diameter isapproximately 0.669 inches. The outer link 104, 132 may be comprised,for example, of at least one of metals, plastics, glass, carbon fiber,etc. In a particular embodiment, the outer link 104, 132 is comprised,for example, of polyphenylsulfone (e.g., Radel® R-5100).

With regard to the inner links 100, FIGS. 17A-17I illustrate variousviews of presently preferred embodiments. These inner links 100 aresimilar to those discussed in the overview above. However, they differin some significant aspects. The length of the inner link 100 preferablyis in the range of 0.01-2.00 inches, and more preferably the length ofthe inner link 100 is 0.353 inches. The outer diameter of the inner linkpreferably is in the range of 0.10-2.00 inches, and more preferably, theinner diameter is 0.354 inches. The inner link 100 may be comprised, forexample, of at least one of metals, plastics, glass, carbon fiber, etc.In a particular embodiment, the inner link 100 is comprised of plasticwith embedded glass fiber (30% by weight).

The inner links 100 are configured to pivot relative to one anotherthrough a maximum pivot angle, and the outer links 104 are configured topivot relative to one another through a maximum pivot angle, as shownfor example in FIGS. 10A-13B. Preferably, the maximum pivot angle of theinner links 100 is no less than the maximum pivot angle of the outerlinks 104. In view of this pivoting relationship, it can be importantfor the links 100, 104 to be configured in such a way to avoid one ormore undesired conditions such as: limiting the articulated probe 10flexion; pinching of an elongated member that may be positioned withinthe links 100, 104; and problems that might occur with the advancementand retraction of the elongated member.

Each of the plurality of inner links 100 and/or outer links 104 may haveone or more channels 108 for receiving an elongated member.Alternatively or additionally, mating recesses in inner links 100 andouter links 104 may create one or more channels between inner core 12and outer sleeve 14. An elongated member may be any one of a tool, aninner cable 102, an outer cable 106, or an inner core 12. Typicalelongate tools include but are not limited to: scissors, scalpels andother cutting tools; graspers such as tissue graspers; energy deliveryelements such as tissue ablation elements, electrocautery andcoagulation elements; cambers such as fiber optic cameras; heatingelements; cooling elements; drug delivery devices; and combinations ofthese. As discussed in the overview, the tool can be used to performvarious operations and one or more cables may be used to control theouter links 104 of the outer sleeve 14 and the inner links 100 of theinner core 12. The channels 108 are configured to form a semi-continuouspassage from link 100, 104 to an adjacent link 100, 104 and can includea liner to facilitate reception of the elongated member. In someembodiments, as shown in FIG. 11A, a channel 108 of an outer link 104includes a first portion 108 a extending through a first portion 104 aof the outer link 104 and a second portion 108 b extending through asecond portion 104 b of the outer link 104. As shown in FIG. 14G, thechannel 108 may have a circumferential flare. The circumferential flareavoids pinching elongated members within the channel 108 and facilitatesrotation of the plurality of links 100, 104 while significantly reducingany difficulty that may be encountered by advancing or retracting anelongated member through the probe 10. Further, the channels 108 ofinner links 100 and/or outer links 104 may be tapered to achieve asemi-continuous passage from link 100, 104 to link 100, 104.

According to one embodiment, the channel 108 in each of the inner links100 and/or outer links 104 is tapered in an amount sufficient to permitthe inner links 100 and/or outer links 104 to pivot through the maximumpivot angle while providing a substantially continuous surface betweenthe channels 108 of the links 100, 104 for receiving the elongatedmember. More preferably, the opening and/or exit of the channel 108 canbe tapered. The tapered openings and exits of the channel 108 avoidpinching elongated members within the channel 108 and significantlyreduce any difficulty that may be encountered by advancing or retractingan elongated member through the probe 10. In addition, the taperedopenings correlate to the radius of curvature of probe 10. According toone embodiment, the taper of the channel 108 is approximately twice themaximum pivot angle. For example, the taper can be approximately 26°degrees and the maximum pivot angle can be approximately 13° degrees.The taper of the channel 108 preferably can accommodate a pivot angle of13° degrees or greater. In sum, the tapered channels 108 are configuredto provide a substantially continuous surface between the channels 108of the links 100, 104 for the reception of the elongated member.

The inner links 100 of the inner core 12 may have the channel 108positioned near a central axis and configured to receive an inner cable102 (the elongated member), as shown in FIGS. 13A-B and 17A-17I. Thechannel 108 within the inner links 100 can have a flared opening.According to one embodiment, the flared opening is positioned off-centerin relation to the central axis of the inner link 100. Positioning theflared opening off-center allows the pivot point of the inner cable 102to change more easily when the pivot point of the inner core 12 maychange due to rotation of the inner core 12 or any other form oftranslational displacement that may occur. Preferably, the diameter ofthe channels 108 of the inner links 100 is greater than the diameter ofthe inner cable 102, which reduces the occurrence of twisting andsawtoothing of the inner links 100. For example, if the channel 108preferably has a diameter in the range of 0.003-0.500 inches (morepreferably approximately 0.043 inches), the diameter of the inner cable102 preferably is in the range of 0.002-1.000 inches (more preferablyapproximately 0.037 inches). By configuring the diameter of the innercable 102 and channel 108 of the inner links 100 to reduce twisting andsawtoothing, the likelihood of pinching or difficulty with advancementand retraction of the elongated member is also significantly reduced.Thus, the channel 108 of the inner link 100 provides a substantiallycontinuous surface between links 100 for the inner cable 102.

The outer links 104 of the outer sleeve 14 also may have the channel 108formed therein for the reception of an elongated member, as shown forexample in FIG. 12A. In this particular embodiment, the elongated membercan be an inner core 12 with a plurality of inner links 100. The channel108 includes a plurality of outer links 104, each having a flaredopening. As shown in FIG. 12A, the flared opening in each of theplurality of links 104 provide a substantially continuous surfacebetween links 104 for reception of the inner core 12. The channels 108of the outer links 104 are also tapered in an amount sufficient topermit an inner core 12 to pivot through a maximum pivot angle whileproviding a substantially continuous surface between the channels 108for the inner core 12. The taper of the channels 108 also allows flexionof the inner links 100. Preferably, the inner flexion of the inner links100 may be greater than or equal to 13° degrees. Thus, the channel 108of the outer link 104 provides a substantially continuous surfacebetween links 104 for the reception of the inner core 12.

A plurality of channels 108 also may be positioned near the outersurface of the outer link 104, as shown in FIGS. 14A-16K. According toone embodiment, three channels 108 are positioned approximately 120°degrees from each other around a circumference of one or more outerlinks 104 making up the outer sleeve 14. The channels 108 of the outerlink 104 are configured to receive an elongated member in the form ofouter cables 104 for controlling the outer sleeve 14. Preferably, adiameter of the outer cables 106 is less than a diameter of the channels108 of the outer links 104, which reduces the occurrence of twisting andsawtoothing of the outer links 104. According one embodiment, thediameter of the outer cables 106 may be in the range of 0.002-1.000inches. In one embodiment, the diameter of outer cables 106 is 0.027inches. The diameter of the channels 108 in each outer link 104 forreceiving the outer cables 106 may be in the range of 0.003-0.500inches. In a particular embodiment, the diameter of the channels 108 ineach outer link 104 are approximately 0.035 inches. By configuring thediameter of the outer cables 106 and channels 108 of the outer links 104to reduce twisting and sawtoothing, the likelihood of pinching ordifficulty with advancement and retraction of the elongated member isalso significantly reduced. Thus, the channels 108 of the outer link 104provides a substantially continuous surface between links 104 for theplurality of cables 106.

A combination of the inner link 100 and the outer link 104 also may beconfigured so as to provide the channel 108 for receiving an elongatedmember. With reference to FIGS. 14A-14I, an inner surface of the outerlink 104 can have a flared indentation 134 which forms one half of achannel 108 for receiving an elongated member in the form of a tool. Asshown in FIGS. 17A-17I the other half of the channel 108 is formed byflared indention 136 on the outer surface of the inner link 100. Thechannel 108 formed by the flared indention 136 of the inner link 100 andthe flared indention 134 of the outer link 104 provides a substantiallycontinuous surface between links 100, 104 for one or more tools.

The outer links 104 and 132 shown in FIGS. 15A-16K can both beconfigured to receive an elongated member in the form of a tool, cable,or other elongated device. With respect to FIGS. 11A and 16A-16K, thechannels 108 of an outer link 104 can be formed by tool side ports 128.The tool side ports 128 extend out from the outer circumference of theouter link 104 and are configured with a channel 108 to receive tools,cables, or other elongated devices. As shown in FIG. 11A, the transitionouter link 132 is positioned between an outer link 104 and an outer link104 with tool side ports 128 along the length of the probe 10. Accordingto one embodiment and as shown in FIGS. 15A-15J, the transition outerlink 132 has one or more recesses 130 that accommodates and funnelstools into an outer link 104 having a tool side port 128. Accordingly,tools configured for use approximately outside the circumference of theprobe 10 can be received by the channels 108 formed by the tool sideports 128 and the recesses 130 of the transition outer link 132. Thechannels 108 formed by the tool side ports 128 and the recesses 130provides a substantially continuous surface between the outer links 104,132 for one or more elongate devices.

The radius of curvature of the articulated probe 10 can depend on thepivot angle of the inner and outer links 100, 104. With respect to FIGS.10A-12B and 14A-I, the outer sleeve 14 may include a plurality of outerlinks 104 having an outwardly extending flange 110. The flange 110 isconfigured to control the pivot angle of the outer links 104 relative toone another. Thus, characteristics of the flange 110 impact the radiusof curvature of the articulated probe 10 that can be achieved.

According to one embodiment, the geometry of the flange 110 determinesthe degree of pivot possible between each of the outer links 104. Withrespect to FIGS. 14D-14E, the flange 110 can have a first engagementsurface 112 and a second engagement surface 114 extending radiallyoutward relative to a first central axis of the outer link 104. Theflange 110 is configured to permit the outer links 104 to pivot relativeto one another and a probe central axis through an outer maximum pivotangle until the first engagement surface 112 of a first outer link 104and the second engagement surface 114 of a second outer link contacteach other. According to one embodiment, the first engagement surface112 and the second engagement surface 114 taper relative to a lineperpendicular to a central axis of the outer link 104. With reference toFIG. 14E, in one particular embodiment, the first engagement surface 112tapers approximately 6.5° degrees and the second engagement surface 114tapers approximately 6.5° degrees. According to this embodiment, theouter maximum pivot angle is no greater than approximately 13° degrees.In alternative embodiments, the taper of the first engagement surface112 and the second engagement surface 114 may be configured so that themaximum pivot angle is greater that 13° degrees, or less than 13degrees. Preferably, the geometry of the flange 110 is configured sothat the radius of curvature of the articulated probe 10 is in the rangeof 10-600 mm. Thus, the geometry of the flange 110 can be used to setthe maximum pivot angle of the outer links 104, which in turn impacts arange of the radius of curvature of the articulated probe 10.

The links 100, 104, 132 can be configured to reduce the occurrence ofirregular or undesired forces (e.g. irregular or undesired frictionalengagement forces) acting between a first and second link 100, 104. Forexample, as shown in FIGS. 14B, 14H, 15B, 15C, 15I, 16B, 16C, 16J, 17C,17D, 17H, the plurality of inner links 100 and outer links 104 mayinclude a first concave portion 120, also referred to as a secondportion and a first convex portion 122, also referred to as a firstportion. A convex portion 122 of a first link 100, 104 can pivotallyengage a corresponding concave portion 120 of a second link 100, 104.According to a particular embodiment, the first link 100, 104 convexportion 122 has a radius of curvature no greater than a radius ofcurvature of the second link 100, 104 concave portion 120. The links100, 104 can be linked together to form an inner core 12 and outersleeve 14. The arrangement of the links 100, 104 (a concave portion 120pivotally engaging a corresponding convex portion 122) allows the innercore 12 and outer sleeve 14 to pivot with a wide range of motion andreduces the occurrence of irregular or undesired frictional or otherforces between links 100, 104 that may interfere with efficientoperation of the articulated probe 10.

As demonstrated above, the physical characteristics of the variousfeatures of the inner core 12 and outer sleeve 14 affect the propertiesand performance of the articulated probe 10 in various ways. Accordingto one embodiment, the geometric dimensions of one or more channels ofan outer link 104 are mathematically related to one or more parametersof outer link 104. These parameters may include: the radius of an end ofouter link 104; the diameter of outer link 104; the pivot angle betweenouter links 104; diameter of the channel such as average diameter of thechannel; the channel location such as the distance of the channel from acentral axis of outer link 104.

It can be advantageous to form the links in a way that facilitatessmooth articulation of one link relative to the other and avoidsundesired mating forces such as irregular frictional engagement betweenadjacent links. With respect to FIGS. 17A, 17B, 17D-17F, 17I and 18 amethod for producing a link 100, 104 for an articulated probe 10 willnow be described. In step 210, the link 100, 104 is molded in a moldingdevice, including forming at least one engagement surface configured toengage an adjacent link 100, 104 in the articulated probe 10. In step212, the link 100, 104 is ejected from the molding device by pressing atleast one ejection pin 124 (see FIG. 17E) against an ejection surface126 of the link 100, 104 that will not engage an adjacent link 100, 104in the articulated probe 10. As shown in FIGS. 17A, 17B, 17D-E and 17I,according to one embodiment, the ejection surface 126 is located in arecess in the link 100, 104. Strategically positioning the ejectionsurface 126 on a link 100, 104 ensures that the ejection surface 126does not affect the interaction of one link 100, 104 with another suchas by positioning any ejection pin imperfections away from the matingsurfaces between adjacent links. Thus, the above-described procedureensures that each link 100, 104 articulates smoothly relative to anotherlink 100, 104.

Cables

As discussed in the overview above, one or more cables may be used tocontrol the outer links 104 of the outer sleeve 14 and the inner links100 of the inner core 12. Further examples of cable configurations aredescribed below. In these configurations, as shown in FIG. 12B, aplurality of outer cables 106 can extend through the plurality of outerlinks 104. The outer cables 106 are configured to control (e.g. steerand transition between flexible and rigid) the outer sleeve 14. In anembodiment, each of the plurality of outer cables 106 has approximatelythe same tensile strength and/or approximately the same cross-sectionalarea.

As shown in FIGS. 13A-13B, an inner cable 102 extends through theplurality of inner links 100. The inner cable 102 is configured tocontrol inner core 12 (e.g. transition between flexible and rigid). Inan embodiment, the tensile strength and/or cross sectional area of theinner cable 102 is related to the tensile strength and/or crosssectional area of the plurality of outer cables 106.

The relationship between the tensile strength and/or cross sectionalarea of the inner cable 102 and the plurality of outer cables 106provide for efficient movement and operation of the articulated probe10. With regard to tensile strength, the inner cable 102 can have atensile strength greater than each of the individual outer cables 106.In some embodiments, the tensile strength of the inner cable 102 isapproximately equal to a combined tensile strength of the plurality ofouter cables 106. In some embodiments, the tensile strength of each ofthe plurality of outer cables 106 is approximately 1/Nth of a tensilestrength of the inner cable 102, where N is the number of outer cables106. For example, the tensile strength of the inner cable 102 and thecombined tensile strength of the outer cables 106 can be in the range of2-500 lbs, and, in some embodiments, is about 30 lbs.

With regard to cross-sectional area, as shown in FIG. 13C, thecross-sectional area (A_(o)) of each of plurality of outer cables 106can be as small as approximately 1/Nth of a cross-sectional area (Ai) ofthe inner cable 102, where N is the number of outer cables. Thisrelationship is particularly, though not exclusively, important in aconfiguration where the cables 102, 106 are formed of the same materialand/or when the probe 10 diameter is minimized.

The material forming the inner and outer cables 102, 106 can impact theconfiguration of the cables. The inner cable 102 and the plurality ofouter cables 106 may be comprised of the same material, which, in someembodiments, can be at least one of steel, polyethylene(UHMW-ultra-high-molecular-weight), plastic, nylon and fluorocarbons,with steel being more preferred in some embodiments. The inner cable 102and the plurality of outer cables 106 can be formed from by amonofilament or braided technique. However, the desired tensile strengthrelationships can also be achieved by using different materials for theinner cable 102 and the outer cables 106.

In sum, the inner cables 102 and outer cables 106 used to control theinner core 12 and outer sleeve 14 can have various characteristics.These characteristics include, but are not limited to the tensilestrength, the cross-sectional area and the composition of the cables102, 106. Configuring the cables based on desired characteristics andrelationships with respect to the inner cable 102 and the outer cables106 determine the stability and other performance parameters of thearticulated probe 10.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventiveconcepts. Modification or combinations of the above-describedassemblies, other embodiments, configurations, and methods for carryingout the invention, and variations of aspects of the inventive conceptsthat are obvious to those of skill in the art are intended to be withinthe scope of the claims. In addition, where this application has listedthe steps of a method or procedure in a specific order, it may bepossible, or even expedient in certain circumstances, to change theorder in which some steps are performed, and it is intended that theparticular steps of the method or procedure claim set forth here belownot be construed as being order-specific unless such order specificityis expressly stated in the claim.

1. (canceled)
 2. A method of controlling an articulated probe includingat least a portion configured to be controllably rigid and flexible,comprising: providing an inner core comprising a plurality of innerlinks; providing an inner cable; extending the inner cable through theplurality of inner links and configuring the inner cable to control theinner core; providing an outer sleeve comprising a plurality of outerlinks; providing a plurality of outer cables; and extending theplurality of outer cables through the plurality of outer links andconfiguring the plurality of outer cables to control the outer sleeve,providing the inner cable extending through the inner links to have atensile strength that is greater than that of each of the individualouter cables extending through the outer links.
 3. The method of claim2, wherein providing the inner cable comprises providing the inner cableto have a tensile strength approximately equal to a combined tensilestrength of the plurality of outer cables.
 4. The method of claim 2,wherein providing the plurality of outer cables comprises providing eachof the plurality of outer cables to have approximately the same tensilestrength.
 5. The method of claim 4, wherein the tensile strength of eachof the plurality of outer cables is approximately 1/Nth of a tensilestrength of the inner cable, where N is the number of outer cables. 6.The method of claim 2, wherein providing the plurality of outer cablescomprises providing each of the plurality of outer cables to haveapproximately the same cross-sectional area.
 7. The method of claim 6,wherein the cross-sectional area of each of the plurality of outercables is approximately 1/Nth of a cross-sectional area of the innercable, where N is the number of outer cables.
 8. The method of claim 2,wherein providing the inner cable comprises providing the inner cablecomprising at least one of steel, polyethylene, nylon or fluorocarbons.9. The method of claim 2, wherein providing the plurality of outercables comprises providing the plurality of outer cables comprising atleast one of steel, polyethylene, nylon or fluorocarbons.
 10. The methodof claim 2, wherein the tensile strength of each of the outer cables isless than or equal to the tensile strength of the inner cable andgreater than or equal to 1/Nth of the tensile strength of the innercable, where N is the number of outer cables.
 11. The method of claim 2,wherein the inner cable has a diameter that is greater than those ofeach of the individual outer cables.